Sainsbury is facing up to 30 years in jail, but Channel Nine reported a plea deal had been struck, agreed on by both the prosecution and the defence.
The deal still needs to be signed off by the judge, who will return to the courtroom on November 1 to announce whether the deal will go through.
The 22-year-old Adelaide woman was arrested at Bogota's El Dorado international airport in April, trying to smuggle 5.8 kilograms of cocaine inside 18 separate packages of headphones.
Earlier this year, Cassie told 60 Minutes that she thought she had accepted a job as a legitimate courier transporting documents for $10,000 plus flights.
"I had outstanding bills, I suppose I took the risk," she said.
The embattled Aussie also claims a ‘mastermind’ named Angelo threatened to kill her family if she didn’t carry out the task, stating he sent her pictures of her mum, sister and fiancé via Whatsapp – evidence that could potentially prove her innocence.
However Cassie states she can not show anyone the messages as she can’t remember the passcode to her phone.